Khalid Benjelloun

Sliding Mode with Time Delay Control for MIMO nonlinear Systems With unknown dynamics

In this paper, the control problem of Multi-Input Multi-Output (MIMO) nonlinear Systems with unknown dynamics is proposed. A novel method based on the Sliding Mode with Time Delay Control (SMTDC) is proposed by combining a Sliding Mode Control (SMC) with saturation (sat) function and Time Delay Control (TDC). This method (SMTDC), allows chattering reduction on control inputs and estimates the amounts of unknown or unmodeled nonlinear dynamics and unexpected uncertainties and cancels them. This algorithm was simulated on the model of the ANAT robot arm system to demonstrate the effectiveness of the proposed design method.

Discrete-time second order sliding mode with time delay control for uncertain robot manipulators

This paper proposes a second order sliding mode combined with time delay controller to track a desired trajectory for robot manipulators with unknown dynamics and external disturbances. The motivation for using second order sliding mode (SOSM) mainly relies on its appreciable features, such as high precision and elimination of chattering in addition that it ensures robustness. However, the SOSM problem is that the unknown dynamics and the disturbances may be amplified, which makes the system unstable. Then, using the time delay allows to benefit from the robustness of the second order sliding mode while reducing its major drawback. The stability and the robustness of the proposed controller is verified by using the classical Lyapunov criterion. The proposed controller is implemented in real time on the seven-degrees-of-freedom (7-DOF) ANAT robot arm and compared with the sliding mode with time delay control (SMTDC) to prove its superiority.

Control of Uncertain Robot Manipulators using Integral Backstepping and Time Delay Estimation

In this paper, a novel controller is proposed and applied for high accuracy tracking trajectory in the workspace of robot manipulators in presence of uncertainties and external disturbances. Most of nonlinear controllers are based on the mathematical model of robot manipulator, but a lot of robotic systems do not have exact model. This novel approach which consists on designing an Integral Backstepping with Time Delay Control (IBTDC) can estimate uncertainties and keep high tracking performance. The proposed controller is able to stabilize the robot system, and also to drive the trajectory tracking errors to converge in finite time. Furthermore, experimental results are given to illustrate the effectiveness of the proposed method applied to the 7-DOF ANAT robot arm.

Current control based on super-twisting algorithm with time delay estimation for a five-phase induction motor drive

Multiphase induction motor drives have gained popularity due to their fault tolerance and better power/current distribution per phase which are very attractive for industrial applications. Current control strategies with the estimation of unmeasurable variables (typically rotor variables) has been recently proposed for multiphase induction drive. This paper proposes a novel current control based on super-twisting algorithm with time delay estimation for a five-phase induction motor drives. This method considers the estimation of rotor variables and disturbances, and also ensures the stability by using Lyapunov theory. Simulation results are provided to show the effectiveness of the proposed method and also to compare with other controllers such as a proportional-integral and a model-based predictive controllers.

Sliding Mode with Time Delay Control for Robot Manipulators

This chapter introduces two controllers design for the trajectory tracking of robot manipulators with unknown dynamics and external disturbances, including: First Order Sliding Mode with Time Delay Control (FOSMTDC), Second Order Sliding Mode with Time Delay Control (SOSMTDC).

Optimal super-twisting algorithm with time delay estimation for robot manipulators based on feedback linearization

Abstract In this paper, an Optimal Super-Twisting Algorithm (OSTA) with time delay estimation is designed based on Input/Output feedback linearization for uncertain robot manipulators. The design procedure consists on three steps. Firstly, an Input/Output feedback linearization is applied to transform the nonlinear model into a linear equivalent one. Secondly, by defining a quadratic performance, an optimal sliding surface will be designed. Finally, a super-twisting algorithm with time delay estimation is proposed for high accuracy tracking trajectory. Lyapunov theory is used to prove the finite-time convergence of the sliding surface and its derivative. This structure is used to estimate unknown dynamics and to reduce the control effort and the chattering phenomenon.

Optimal posture prediction of human lower limb

In this paper, a new posture prediction method is proposed and evaluated on human leg, as being a physiologically constrained three-link arm. The main posture prediction solution is focused on optimizing the manipulability and the human performance of the leg. The forward kinematics is used to define the feasible workspace of the human leg in sagittal plane. Using an effective optimization-based human performance measure that incorporates a new objective function of musculoskeletal discomfort, the optimal posture is obtained.

Optimal 3D Kinematic Analysis for Human Lower Limb Rehabilitation.

The majority of the kinematics analysis carried out on the human body are usually available only for use in the sagittal plane. Limited studies were interested in this analysis in all three planes (sagittal, transverse, and frontal) where motions of all joints occur. The aim of this paper is to develop a new optimal kinematic analysis of human lower limbs in threedimensional space for a rehabilitation end. The proposed approach is focused on optimizing the manipulability and the human performance of the human leg, as being a physiologically constrained three-link arm. The obtained forward kinematic model leads to define the feasible workspace of the human leg in the considered configuration. Using an effective optimization-based human performance measure that incorporates a new objective function of musculoskeletal discomfort, the optimal inverse kinematic (IK) model is obtained.

Non-singular Terminal Second Order Sliding Mode with Time Delay Estimation for Uncertain Robot Manipulators.

In this paper, a second order sliding mode with time delay estimation based on non-singular terminal sliding surface is presented for high-accuracy tracking trajectory of uncertain robot manipulators. The design of the proposed controller is based on a non-singular terminal sliding surface that overcomes the problem of singularity and the restrictions of the exponent in classical terminal sliding surface. Then, a second order sliding mode control scheme with time delay estimation is proposed to eliminate the chattering phenomenon and to estimate the uncertainties and disturbances. Lyapunov theory is used to prove the finite-time convergence of the sliding surface and its derivative. Finally, simulation results are presented to illustrate the effectiveness of the proposed method.

Second order sliding mode with time delay control for uncertain robot manipulators

This paper proposes a second order sliding mode combined with time delay controller to track a desired trajectory for robot manipulators with unknown dynamics and external disturbances. The motivation for using second order sliding mode (SOSM) mainly relies on its appreciable features, such as high precision and elimination of chattering in addition that it ensures robustness. However, the SOSM problem is that the unknown dynamics and the disturbances may be amplified, which makes the system unstable. Then, using the time delay allows to benefit from the robustness of the second order sliding mode while reducing its major drawback. The stability and the robustness of the proposed controller is verified by using the classical Lyapunov criterion. The proposed controller is implemented in real time on the seven-degrees-of-freedom (7-DOF) ANAT robot arm and compared with the sliding mode with time delay control (SMTDC) to prove its superiority.